找出参数的平均值

Question

I am trying to calculate the average of parameters by passing them to an array but I am getting the following error. So I have doubt am I doing it right?

Here is my code

arr= @r1+@r2+@r3+@r4+@r5
    @current_user_satisfaction= arr.inject{ |sum, el| sum + el }.to_i / arr.size

Where I am getting r1, r2,r3,r4 from the DB. I am getting the following error

: syntax error, unexpected tIDENTIFIER, expecting keyword_end @current_user satisfaction= arr.inject{ |sum, el| sum +... ^

What was my problem where is my error. I actually started learning ROR very recently.

This what I am writing to do

I have as set of variables which I am taking from db based up user_id and company_id the variables are

  @r1=company_rating.collect(&:r1)
  @r2=company_rating.collect(&:r2)
  @r3=company_rating.collect(&:r3)
  @r4=company_rating.collect(&:r4)
And I wanted to find the avg of all those variables. 

So I am doing it like arr = [@r1,@r2,@r3,®r4] @current-user_satisfaction= arr.sum.compact /arr.size But I am getting an error / is undefined and Why I am doing compact is because I have sum of the nil values in that

So please help how do this.

Answer 1

This is not an array!

arr= @r1+@r2+@r3+@r4+@r5

This is a sum. Should be arr= [@r1,@r2,@r3,@r4,@r5] Additionally you missed dot between @current_user and satisfaction .

Also it is not as it should be done in rails. Could you show us how those variables are set?

Answer 2

First, You need to create the array like this

arr= [@r1,@r2,@r3,@r4,@r5]

The error you are getting is about the . dot you missed between @current_user and satisfaction . Change it accordingly and you will get it working.

As far as I think, you don't need an array there. if you are doing, arr= @r1+@r2+@r3+@r4+@r5 , it is already calculating the sum of values, why you need to put them to array and go for a loop.

However, If you still want to use array, instead of arr.inject{ |sum, el| sum + el } arr.inject{ |sum, el| sum + el } , you can use arr.reduce('+') , which does the same thing of calculating sum of all array values. This has nothing to do with your problem, but makes your code more understandable.